Nanocomposite-based ultrathin polarization beamsplitter

In terms of the effective medium approximation, the optical properties of heterogeneous composite materials with disordered nanosized metal inclusions of spheroidal shape with plasmon resonances lying in the visible spectral range are studied. The conditions are analyzed under which the optical characteristics of the composite with axial symmetry of the inclusion orientation distribution with respect to a certain preferential direction significantly depends on the electric field direction in the electromagnetic wave. It is shown that, in the vicinity of the plasmon resonance of inclusions, the composite layer of subwavelength thickness may exhibit a high polarization selectivity in both reflection and transmission with moderate absorption. The effect of the orientational disorder of inclusions on the optical characteristics of a polarization splitter of this kind is discussed. The predictions based on equations of quasi-electrostatic effective-medium model agree well with the results of exact numerical solution of the Maxwell equations.